1. Field of the Invention
The present invention relates in general to high-vacuum oil refining system and process and, more particularly, to an improvement in such system and process for easily separating the crude oil into light oils and heavy oils using a pressure reduced thermal cracking device and a vacuum gas specific gravity centrifugal separator, and for producing varieties of light oils using the multi-step light oil vapor gas specific gravity vacuum centrifugal separators, and for producing varieties of heavy oils through high-vacuum distillation using high-vacuum creating and sustaining device and vacuum oil recycling and supplying system as well as heavy oil vapor gas specific gravity high vacuum centrifugal separators, and thereby refining and desulfurizing the sulfur contained crude or heavy oil without using expensive desulfurizing process.
2. Description of the Prior Art
Known oil refining processes are generally classified into two-types, the atmospheric pressure distillation and pressure reduced distillation process. In the typical pressure reduced distillation process for oil refining, it has been noted that the desired high-vacuum distillation at 1-10.sup.-4 Torr can not be performed due to inferior technique for generating and keeping the high vacuum.
Therefore, the conventional pressure reduced distillation process has to be performed at a higher temperature than high vacuum distillation. With the high temperature distillation, high heavy oil and super-high heavy oil, both heavy oils having high viscosity, have been distilled in the distillation chamber through vaporization at high temperature ranged from 370.degree. C. to 570.degree. C., being heated beyond the thermal cracking point of the oil. In this regard, the typical pressure reduced process for oil refining has a problem that the process merely produces inferior quality oil and requires large and complicated refining system and thereby increasing the cost and specially causing danger in oil cracking process.
In the case of high viscosity oil obtained through vaporization and distillation at constant temperature and at constant vapor pressure, it is very difficult to produce high purity oil of uniform quality as there is neither device nor technique for centrifugally separating the vaporized gases by specific gravity. In addition, when producing the light oils using typical heavy oil cracking system, the cracking system should use a high temparature, high pressure thermal cracking column having the maximum pressure of 170 kg/cm.sup.2 and the maximum temperature of 450.degree. C. Therefore, this cracking system is enlarged in its scale and increased in the system cost and also may cause danger due to the super-high pressure of 170 kg/cm.sup.2.